There has been proposed an electronic equipment, such as a portable radio receiver or the like, which is provided with a manual rotary driver and a generator having a rotor and operative to generate electric power when the rotor is driven to rotate by the manual rotary driver. When such an electronic equipment is put into actual use, for example, the manual rotary driver is rotated manually by a user to drive the rotor of the generator to rotate, so that the generator is put in operation for generating electric power. The electric power obtained from the generator is supplied to a secondary battery or a condenser for accumulating electric power, such as an electrical double layer condenser, connected with the generator as a load and stored or accumulated in the secondary battery or the condenser for accumulating electric power. The electronic equipment, such as the portable radio receiver or the like, is operative to work with a power source of the secondary battery or the condenser for accumulating electric power in which the electric power from the generator is stored or accumulated.
Since such an electronic equipment containing the generator as mentioned above generates electric power for itself as occasion demands, it can be put in operation without any external power source and being concerned about consumption in a battery contained therein. Accordingly, it is spontaneously considered that the electronic equipment containing the generator is used for countermeasures against various calamities. For example, under a situation where a commercial electric power supplying system is visited by a calamity, such as a big earthquake, a big fire and so on so as, to be destroyed and an inconvenience in which it is very difficult to obtain new batteries is raised by the calamity, the electronic equipment containing the generator can be operative to function normally.
Then, it is required for the electronic equipment containing the generator to be made portable and easily carried and used with simple operations by a user when a calamity occurs. Consequently, it is desirable that each of a generating apparatus comprising the generator contained in the electronic equipment and the manual rotary driver for driving the rotor of the generator to rotate and a power supplying portion for supplying a load connected to the generator with electric power is miniaturized in weight and size so that high efficiency is obtained.
As for the generating apparatus provided to the electronic equipment containing the generator, it has been proposed that such an apparatus as to comprise an AC generator having a stator arranged around a rotary shaft and a rotor secured to the rotary shaft and having an annular portion surrounding the outer peripheral portion of the stator and a manual rotary driving mechanism having a rotary driver which can be manually rotated and an accelerator for increasing the rotation of the rotary driver to be transmitted to the rotor of the AC generator.
In the generating apparatus thus provided, when the rotary driver of the manual rotary driving mechanism is rotated manually, the rotation of the rotary driver is increased by the accelerator and the increased rotation is transmitted from the accelerator to the rotor of the AC generator so as to cause the AC generator to generate electric power. The electric power obtained from the AC generator is rectified to be converted to direct-current (DC) electric power which is supplied to a secondary battery or a condenser for accumulating electric power to be stored therein.
In the generating apparatus which comprises the AC generator and the manual rotary driving mechanism having the rotary driver and the accelerator as mentioned above, when the operation for generating electric power is carried out, a torque necessary for rotating the rotary driver of the manual rotary driving mechanism is relatively large and therefore there has been a problem that a user who rotates manually the rotor of the AC generator through the rotary driver and the accelerator of the manual rotary driving mechanism, meets with such resistance as to be generally expressed "heavy" and is required to spend a relatively great deal of labor and further it is feared that it is substantially impossible for the user to rotate appropriately the rotary driver of the manual rotary driving mechanism.
The torque necessary for rotating the rotary driver of the manual rotary driving mechanism so as to rotate the rotor of the AC generator is increased to be relatively large in the following manner, for example.
When the rotation transmitted from the rotary driver of the manual rotary driving mechanism through the accelerator to the rotor of the AC generator is steeply increased by the accelerator for the purpose of rotating the rotor of the AC generator at a relatively high speed, the torque necessary for rotating the rotary driver of the manual rotary driving mechanism so as to rotate the rotor of the AC generator through the accelerator is increased, and especially, an initial torque necessary for the incipient stage of the rotation of the rotor of the AC generator is steeply increased. In addition, when the electric power obtained from the AC generator is rectified to be converted to DC electric power which is supplied to the secondary battery or the condenser for accumulating electric power to be stored therein, a torque necessary for rotating the rotor of the AC generator becomes relatively large in response to an output current of the AC generator which increases by reason of the following.
Generally, in a generator having a stator and a rotor, for example, a coil wound on a magnetic core is provided on the stator and a permanent magnet opposite to the magnetic core on which the coil is wound is provided on the rotor. When the permanent magnet provided on the rotor is moved to the magnetic core on which the coil is wound, electromotive force is generated in the coil and a current based on the electromotive force flows through the coil to form an output current of the generator on condition that a load is connected with the generator. When the current flows through the coil, the magnetic core on which the coil is wound is magnetized by that current, so that magnetic attractive force and magnetic repulsive force are generated between the magnetic core and the permanent magnet provided on the rotor and electromagnetic brake acts on the rotor. Accordingly, a torque overcoming the electro-magnetic brake acting on the rotor is necessitated to rotate the rotor. The larger the current flowing through the coil wound on the magnetic core, namely, the output current of the generator is, the larger the electromagnetic brake acting on the rotor becomes. Consequently, the larger the output current of the generator is, the larger the torque necessary for rotating the rotor becomes.
Accordingly, it is an object of the present invention to provide a generating apparatus comprising an AC generator and a manual rotary driving mechanism having a rotary driver and an accelerator, in which the rotation of the rotary driver is increased by the accelerator and the increased rotation is transmitted from the accelerator to a rotor of the AC generator so as to cause the AC generator to generate electric power when the rotary driver is rotated, and by which force required to act necessarily on the rotary driver to rotate the same is effectively reduced and therefore the rotary driver can be easily and appropriately rotated by relatively small force.